Thanks Jonathan! We very much appreciate all the support! GitHub is newer than say sponsoring us via PayPal, so that might be why - and some see GitHub as being a platform for more highly tech-savvy folk (though that is only true if you want to read the code - we've had a lot of great feedback from people on how much easier our new GitHub template is to create issues for less-technical users). We are grateful to all our sponsors, however they find it easiest to contribute :)

I'd guess the donation mechanism on the website is more popular. I know that's the one I used when I set up my monthly donation years ago, because I could simply use Paypal and never have to think about it. At that time, I didn't even know Github let users sponsor.